Brake light flashing 5kcs

[Fred Munro]

John;

    The lingering "brake" warning on your 20v is likely due to a leaking
check valve in the bomb. Check your reservoir Pentosin level just after you
shut off the car and check it again in the morning - you'll likely find the
level has risen overnight from the fluid leaking out of the bomb back into
the reservoir. This is also common with the UrS cars - mine does it.
    Replacing a bomb with passes a 20+ pump test would be rather foolish
now, wouldn't it? The point I'm making is that before you dive into the
cheap switches and pump pressure testing, do the bomb test - it's simple,
free, fast, and if the bomb is over 7 years old, it is quite likely the
culprit.
    In this particular case, the additional info about the overflowing
reservoir points to a pump problem.

Fred Munro
'94 S4

----- Original Message -----
From: "John Larson" <j.d.larson at verizon.net>
To: "Fred Munro" <munrof at sympatico.ca>; <mannix at rmsolo.org>;
<quattro at audifans.com>
Sent: Saturday, November 24, 2001 5:45 PM
Subject: Re: Brake light flashing 5kcs


> I've seen cars with the lingering "Brake" warning even with a new
> accumulator.  My 20v does this.  Replacing an expensive accumulator that
> passes the 20+ pump test isn't something I'd even consider.  The frequency
> of leaking/failing warning switches is high, and they're cheap.  Without
> testing the pressures, it's difficult to determine the source of any brake
> boost system failure.  In this case, we're not even sure which system is
the
> problem.  Is it the brake system or the booster system?  Is it fluid level
> or pressure?  With the report of an overflowing reservoir, but also the
> absence of a sender, is the warning light even related to the boost
system?
> John
> ----- Original Message -----
> From: "Fred Munro" <munrof at sympatico.ca>
> To: "John Larson" <j.d.larson at verizon.net>; <mannix at rmsolo.org>;
> <quattro at audifans.com>
> Sent: Friday, November 23, 2001 6:39 PM
> Subject: Re: Brake light flashing 5kcs
>
>
> > Hi John;
> >
> >     I had two indications the bomb was dead on my '91 200q. The light
> stayed
> > on for over 30 seconds after I started the car (bomb discharged and
> > repressurizing), and the light flashed under heavy braking (system
> pressure
> > too low). The bomb had 3 pumps in it. Replacing the bomb eliminated the
> > light issues. The car braked normally, but fortunately I had no occasion
> to
> > stop in a hurry.
> >      If the bomb is more than 7 years old, I'd tend to suspect the bomb
> > before failure of the other components. Without the backup provided by
the
> > bomb, it is possible to pull the system pressure down below the warning
> trip
> > for the light with the engine running if you brake hard enough.
> >
> > Fred Munro
> > '94 S4
>
>